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Original file

Original / Factory · Petrol · 4.2 Biturbo 450hp

Audi RS6 4.2 V8 Turbo original file Bosch HW 0261208728 · 4D1907558F · SW 370934

Audi RS6 4.2 V8 Turbo Turbo Petrol 331 kW (450 HP) Original

2003, Turbo petrol, 331 kW (450 hp)

450 HP Factory calibration Stock backup file, 560 Nm, Petrol

Calibrated ECU file for 0261208728 (SW 370934). Checksum-corrected, ready to flash. Delivered instantly via secure download after payment.

Performance projection

Matched engine: 4.2 Biturbo 450hp, BCY, 4.2L, Petrol. Engine #662 in our gains database.

0110220330440 1000200030004000500060007000 450 HP +0 560 Nm +0 HP Nm RPM 0140280420560
Stock · Factory · HP (left) · Nm (right) · Curve shape typical for this ECU family
Power
450 HPfactory calibration
Torque
560 Nmfactory calibration

Real data from Gains API. Dyno curve = typical ECU-family projection. Final gains depend on fuel, altitude, wear.

How it works

  1. Read your ECU

    With KESS, KTAG, AutoTuner or Flex. Keep the read: it is your way back.

  2. Match the numbers

    Your read must show hardware 0261208728 and software 370934.

  3. Pay and download

    Card, Apple Pay or Google Pay. The file is in your account straight away.

  4. Write it and drive

    Write it back the way you read it. Not right for your car? We correct it free.

What the car needs

Required modifications: Factory, Petrol.

Hardware

  • Factory hardware: no modifications required

Software / calibration

  • OEM calibration restored (recovery / immobiliser / coding work)

Original files are used to revert to factory state, repair after a faulty tune, or recover an ECU before service work.

Vehicle & ECU specifications

Exact vehicle, engine and ECU identifiers this calibration file is written for. Cross-check against your ECU before flashing.

Vehicle make Audi
Vehicle model Rs6
Model year 2003
Displacement 4.2 L
Fuel / Induction Petrol
Factory power 331 kW (450 HP)
ECU manufacturer Bosch
ECU ID 4D1907558F
ECU hardware 0261208728
ECU software 370934
Calibration stage Original (Factory)
Cylinder capacity 4172 CC
Compression ratio 9,3 : 1
Bore × Stroke 84,5 X 93,0 mm
OEM engine code BCY
File format BIN / ORI
Checksum Pre-corrected (ready to flash)
Delivery Instant download after payment

Engine performance matrix

Power, torque and fuel-economy figures for every tuning stage on this engine, sourced from the tuning-database Gains API. Values are healthy-engine crank numbers; real on-road gains vary with fuel, altitude and mechanical condition.

Engine4.2 Biturbo 450hp CodeBCY Displacement4.2L Capacity4172 CC Compression9,3 : 1 Bore × Stroke84,5 X 93,0 mm FuelPetrol Engine ID#662
Stage Power Torque Δ HP Δ Nm
Original / Factory 450 HP 560 Nm — —
Stage 1 520 HP 725 Nm +70 (15.6%) +165
Stage 2 622 HP 964 Nm +172 (38.2%) +404
Stage 3 743 HP 1012 Nm +293 (65.1%) +452
Stage 4 878 HP 1063 Nm +428 (95.1%) +503
Fuel economy gain (vs. factory map, same driving profile): combined cycle −8% , full-load cruise −12%. Diesel calibrations typically net bigger combined-cycle savings thanks to shorter duty-cycle on low-load driving.

About this calibration file

This is the factory (original) ECU calibration for the 2003 Audi Rs6 4.2L Petrol, extracted from a genuine stock control unit. Use it as a verified backup before flashing any performance tune, or as a reference when recovering an ECU from a failed write.

This file matches a Bosch ECU with hardware number 0261208728 and software version 370934. Verify both identifiers in your flashing tool before writing — an ID mismatch is the most common cause of a bricked ECU. If you are unsure, upload a read of your original file via the file-request wizard and our engineers will confirm compatibility before you flash.

The file is delivered as a ready-to-flash BIN (and ORI backup where applicable) compatible with all major tools — KESS V2/V3, KTAG, AutoTuner, CMDFlash, Dimsport New Genius, MPPS, Flex, BFlash, PCMFlash, MMFlash — via OBD, bench or boot-mode as supported by your ECU family. Checksums are pre-computed and verified; no additional checksum tool is required. All files include a free revision if post-flash logs reveal a fuelling, boost or EGT issue.

Frequently asked questions

The file is written for the exact ECU hardware 0261208728 (Bosch) listed in the specifications. Read your ECU with any supported tool (KESS, KTAG, AutoTuner, CMD, etc.) and compare the hardware + software numbers against the ones on this page. If they match exactly, the file is a direct fit. If you're not 100% sure, upload your original read via the file-request wizard and our engineers will confirm within minutes — no cost, no obligation.

Two reasons. First, if your ECU write failed mid-flash and you need a verified stock image to recover from — this file restores the unit to the exact calibration it left the factory with. Second, if you plan to experiment with a tune and want a known-good rollback point that is guaranteed identical to a Audi dealer programming.

Instant. As soon as the payment clears, the file appears under Downloads in your account and the link is emailed to you. It does not expire: sign in and download it again whenever you need it.

Pre-corrected. Every tuning file we sell is processed through CHKSuite (our in-house checksum engine) before it reaches your download link. You can flash it directly with KESS, KTAG, AutoTuner, CMD, Dimsport or any other supported tool — no extra checksum step required. A zero-CRC write to a modern Bosch/Siemens/Delphi ECU bricks the unit, so this is non-negotiable.

Contact us on WhatsApp or through the dashboard support thread. Free revisions are included for the same stage on the same ECU — send us a live log (via VCDS, INPA, EcuConnect, OBDeleven or similar) and we'll adjust timing, boost, rail pressure or smoke limits and re-issue the file. A failed flash itself (write aborted, bricked ECU) is recoverable with our Original file and a bench tool.

Product details

This product contains a complete original ECU backup (stock file) for Audi RS6 4.2 V8 Turbo 2003 Turbo-Benzin 331KW with Bosch 0261208728 and software ID 4D1907558F (Bosch software number 370934 ( 1037370934 )). This original file corresponds to a factory engine output of approximately 331 kW (~450 HP). This file is ideal for ECU cloning, restoring the car back to stock and using it as a safe base for future remaps.

All ECU tuning files from TUNING-DATABASE are prepared for professional use. They are useful whenever you search by ECU ID, hardware or software number such as 0261208728, 4D1907558F, 370934 (1037 + SW code). Use this file for diagnostics, cloning, recovery or as a base for custom remapping.

SHA-256 fingerprint38C88B19 D3193208 5A1A483E F3D653DD 3AD0543D 69E20A4B DFA59232 617F731B